Scientists shed light on riddle of Sun's explosive events

Sep 24, 2012 by David Sims

A computer visualization of the sun (red sphere) and its magnetic field lines (orange and aquamarine). The close-up shows the final stage of the emergence of magnetic fields from under the solar surface and the associated X-ray emissions. This sophisticated computer model is used to investigate the drivers of harmful space weather phenomena, including coronal mass ejections. Credit: Cooper Downs, Predictive Science, Inc.

(Phys.org)—Four decades of active research and debate by the solar physics community have failed to bring consensus on what drives the sun's powerful coronal mass ejections (CMEs) that can have profound "space weather" effects on Earth-based power grids and satellites in near-Earth geospace.

In a paper just published in Nature Physics, an international team of space scientists, including a researcher from the University of New Hampshire's Space Science Center (SSC), explains the mysterious physical mechanisms underlying the origin of CMEs. Their findings, based on state-of-the-art computer simulations, show the intricate connection between motions in the sun's interior and these eruptions and could lead to better forecasting of hazardous space weather conditions.

CMEs are clouds of magnetic fields and plasma ­– a hot gas composed of charged particles. The fastest and most powerful of these events can explode from the sun at speeds of more than a million miles per hour and release more energy than the current worldwide stockpile of nuclear weapons.

"By studying CMEs we learn not only about the drivers of space weather but also about the structure of the atmosphere of the sun and other sun-like stars," says lead author Ilia Roussev of the Yunnan Astronomical Observatory, Chinese Academy of Sciences (CAS) and the Institute for Astronomy at the University of Hawaii at Manoa.

Geomagnetic storms caused by CMEs can disrupt power grids, satellites that operate global positioning systems and telecommunication networks, pose a threat to astronauts in outer space, lead to rerouting of flights over the polar regions, and cause spectacular auroras. The storms occur when a solar eruption hits Earth's protective magnetic bubble, or magnetosphere.

The Nature Physics paper, titled "Explaining fast ejections of plasma and exotic X-ray emission from the solar corona," provides an explanation of the origin of fast ejections of magnetized plasma from the sun's atmosphere and associated X-ray emissions. It thus demonstrates a fundamental connection between the magnetic processes inside the sun's interior and the formation of CMEs.

"Through this type of computer modeling we are able to understand how invisible bundles of magnetic field rise from under the surface of the sun into interplanetary space and propagate towards Earth with potentially damaging results", says SSC researcher Noé Lugaz of the UNH Institute for the Study of Earth, Oceans, and Space. He adds, "These fundamental phenomena cannot be observed even with the most advanced instruments on board NASA satellites but they can be revealed by numerical simulations."

A long-standing goal of the solar physics community has been the forecasting of solar eruptions and predictions of their impact on the Earth. In the paper, the authors note, "the model described here enables us not only to capture the magnetic evolution of the CME, but also to calculate the increased X-ray flux directly, which is a significant advantage over the existing models."

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User comments : 5

The reductionist approach to solving this problem can, as an option, set as its boundary to what it considers the point at which the theoretical framework breaks down. That's arguably what's actually happening here, because once one *also* considers the failure of the solar wind to appreciably decelerate even as it passes the Earth's orbit, then the entire framework becomes dubious. In other words, by ignoring the evidence for a solar electric field, it becomes more palatable to consider the importance of some hidden dynamo deep within the Sun, as the primary mover-and-shaker for what we see.

But, the solar wind's enigmatic acceleration is not going to go anywhere. The enigma is still there, and we very likely deceive ourselves that we can solve the problem we are currently focused upon in this reductionist manner, by simply ignoring that which this theoretical framework, in truth, struggles to explain.

To solve complex problems, we have to be willing to look at other paradigms.

"Through this type of computer modeling we are able to understand how invisible bundles of magnetic field"

Bundles of magnetic field? That's a funny and an ill-conceived notion. As Hannes Alfven once said,"Students using astrophysical textbooks remain essentially ignorant of even the existence of plasma concepts, despite the fact that some of them have been known for half a century. The conclusion is that astrophysics is too important to be left in the hands of astrophysicists who have gotten their main knowledge from these textbooks. Earthbound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory."[Lamenting the traditional neglect of plasma physics]

For a clear explanation, with diagram, of CME's and prominences check out the bottom of this page;

EU/PC religion sockpuppets? And "neglect of plasma physics" is actually understanding it and its limitations, an obvious lack in EU/PC antiscientist pattern searchers who can never present one quantified prediction. That is why it can be sometimes neglected and we still arrive at successful predictions.

Anyway, it is funny how a successful (quantified) prediction based on knowledge of solar conditions and especially its fusion kinetics are suddenly mapped to 'we know nothing, and we need "paradigms"'. (O.o)

Meanwhile, in the real world ordinary competent laymen understand that science progress and roughly how.